This happened about 6 months ago. I park my car and walk towards the entrance. I see this teen, really tall but very skinny walking back and forth nervously near the entrance. He kept pulling down his ski mask over his face and then taking it off.
For some reason, none of the shoppers or the Walmart greeters at the door seemed to notice or care. My panic mode set in and I waved at a police cruiser who was parked a few yards to the right, but the perps view was blocked due to a pillar.
The kid continues his nervous walk and I see this cop walking slowly to the kid from behind. The kid was so nervous he didn't notice the cop or his cruiser. All it took was a tap on his shoulder and he was taken in without incident. He wasn't armed, but if he did pull the robbery, he would have had some serious injuries to deal with.